As is known in the art, in some missile radar systems, radio frequency (RF) antennas have been placed in front of and separate from a radome structure in which an optical (e.g., IR) sensor resides. The antennas are spaced from the radome structure in an attempt to avoid signal degradation issues. However, such designs limit the number of antennas that can be used in the respective radar system and such design approaches may result in aerodynamic issues for radar systems disposed on a missile.
For example, in some radar systems having a limited number of antennas, the radar system may only be able to track one target at a time or track multiple targets with a limited bandwidth. Further, such radar systems are typically designed and used for one specific type of application.
Some beamforming applications are designed to track multiple targets. However, such systems require much more complex electronics and space and therefore, are not appropriate for use in applications having a limited amount of space (e.g., seeker systems, missile systems, etc.). For example, a broadband, directional antenna may be needed for high speed applications. However, these antennas can take up valuable space in a center portion of an antenna system where an optical or RF seeker antenna is commonly located. Thus, such antennas are too large to allow to be included in a system with the optical and/or RF seeker portion of the system. Furthermore, many small, broadband, directional antennas are not conformal and thus not appropriate for inclusion on high speed airframes external to the radome.
Further, in some embodiments, whether internal or external to the radome, such broadband, directional antennas may interact with the optics. For example, when the antenna elements are placed external to the radome and proximate to or in front of optical sensors, such as on a missile seeker, the proximately located antenna structures may become heated (e.g., due to friction) and thus the RF antennas can become heat radiators. This results in interference with infrared (IR) sensors when the RF antennas are proximate the IR sensors.